1. Field of the Invention
The present invention relates to a light-emitting device for a motor vehicle headlamp and also to a headlamp equipped with the device. Although provided more particularly for use in foglamps, the invention may also be used in high-beam lamps, low-beam lamps or any other type of vehicle headlamp that is used to light the roadway.
2. Description of the Related Art
Headlamps that use light-emitting diodes as light sources are known. Although such sources are sometimes known as cold sources since they produce little or no radiant heat, they need to be cooled. This is because an excessive increase in the temperature impairs the intensity of the beam emitted. In addition, it poses a risk for their supply of current, since the latter is realized by virtue of a connection which would become defective if the temperature exceeded a particular threshold.
In order to solve this problem, it is currently known to provide such headlamps with a heat dissipation device, such as a finned radiator, in a heat exchange relationship with the diodes. An opening is made in the housing of the headlamp so that the radiator can emerge therefrom and exchange heat by natural convection with the ambient air outside the housing.
Such a solution increases the number of components to be employed. In addition, it has a limited aesthetic nature, which is not of course of consequence as long as the housing of the headlamp is concealed under the body of the vehicle, but which is not satisfactory when the headlamp is visible, in particular in the case of additional headlamps, that is to say headlamps intended to be mounted on the outside of the vehicle.